Steinhardt and Turok—working closely with a few like-minded colleagues—have now developed these insights into a thorough alternative to the prevailing, Genesis-like view of cosmology. According to the Big Bang theory, the whole universe emerged during a single moment some 13.7 billion years ago. In the competing theory, our universe generates and regenerates itself in an endless cycle of creation. The latest version of the cyclic model even matches key pieces of observational evidence supporting the older view.

This is the most detailed challenge yet to the 40-year-old orthodoxy of the Big Bang. Some researchers go further and envision a type of infinite time that plays out not just in this universe but in a multiverse—a multitude of universes, each with its own laws of physics and its own life story. Still others seek to revise the very idea of time, rendering the concept of a “beginning” meaningless.